The advent of higher-bandwidth Internet services over existing communication networks has created an alternative method to deliver video programming. However, Internet Protocol, or IP, based digital video distribution is capable of utilizing network infrastructures other than those used by the traditional Internet services. IP video or IP television (IPTV) is the transmission of television signals (digital video and audio) through data networks such as, for example, DSL, cable modem or wireless broadband.
Delivering video over IP is bandwidth intensive and, therefore, bandwidth to the home is a precious commodity due to the fact that broadband-quality video consumes a significant portion of a communication channel's data transmission capacity. IPTV services may be on a subscription basis paid for by the recipient for access to the network and requires an IP set-top box and an associated display device or TV within a subscriber premises, rather than a conventional cable television (CATV) set-top box. In order to retain customers, network access providers such as telephone companies may wish to provide IPTV over their existing infrastructure. This requires that they evolve their network.
When accessing a network such as the Internet, for example, a subscriber might connect through a high speed connection, such as Digital Subscriber Link, or DSL, that uses the same pair of copper wires as a regular telephone line. The pair of copper wires is capable of carrying a much greater bandwidth than what is typically demanded for voice. To use DSL, there is a DSL modem or transceiver at the subscriber's location. There is also a DSL Access Multiplexer (DSLAM) to receive subscriber connections at the location of the DSL service provider such as an Internet service provider or a telephone company. The DSLAM aggregates the subscriber connections onto a single high-capacity connection to the Internet. One way for a telephone company to provide DSL service is to have a DSLAM at its central office.
Also, many network operators oversubscribe the bandwidth on their network to maximize the return on investment in their network infrastructure. Oversubscribing bandwidth means the bandwidth a user subscribes to is not always available to them. Subscribers compete for available bandwidth and they receive more or less bandwidth depending on the amount of traffic from other subscribers on the network at any given time. When a network becomes increasingly congested, packets are dropped. Therefore, audio and video becomes corrupt due to packets being dropped when a link to a subscriber is oversubscribed.
Because there is never enough bandwidth, the traditional solution of the DSL service providers is to increase transmission line throughput, such as with equipment of significant cost, or reduce the bit-rate per channel for better encoding. However, services delivered to the home must be perceived to be of high quality and, thus, bit-rate reduction may not always be a suitable alternative. Therefore, in order to improve their video system, there is a need to intelligently manage and optimize the data rate for video services across a broadband connection such as DSL. In particular, individualized link bandwidth allocation is needed to manage and optimize bandwidth.